Albedo map

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''TBD: See [[Normal map]] for examples.''
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The albedo map defines the base RGB color of each [[texel]]. It is configured using a [[texture.txt file]] which is directly referenced from the material (usually within a [[mesh file]] although sometimes from the asset's [[config.txt]] directly).
  
If no alpha channel is specified, the diffuse map will default to a full white alpha channel.
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The albedo map is the [[Physically Based Rendering]] equivalent of the ''diffuse map'' used in legacy materials. At a casual glance, these fill the same role and the terms can be interchanged, however to be strictly accurate the albedo is the surface color irrespective of any lighting effects, whereas the diffuse map frequently included burned-in lighting (pre-baked [[ambient occlusion]], etc.) The albedo map should never include pre-baked lighting, as that would interfere with the correct operation of the PBR equations.
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= Color Space =
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Unless otherwise specified by the [[Material Types|material]] in use, the RGB channels use the sRGB color space.
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= Alpha Channel =
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It is common for (semi-)transparent materials to store the alpha blend factor (ie. opacity level) in the albedo map's alpha channel. Materials which are fully opaque may use the albedo's alpha channel for some other purpose, or not at all.
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If no alpha channel is specified, the outcome is identical to a fully white (1.0) alpha channel.
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Some legacy [[Material Types|material types]] offer automatic selection of [[alpha blending]], [[alpha masking]] or opaque rendering modes based on the contents and configuration of the albedo map. This introduces uncertainties when texture replacement is used as to what material configuration will result. [[TRS19]] materials do not attempt this, and instead rely on the content creator to select the appropriate material type.
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= Examples =
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''TBD: See [[Normal map]] for examples.''
  
The alpha channel in the diffuse map has a context-sensitive interpretation. In gloss and bump-gloss materials, the alpha channel indicates a blend between the gloss reflection (black alpha) and the diffuse texture color (white alpha).
 
  
In most other materials, the alpha channel is used as an opacity control with black being full transparency and white being fully opaque. This is referred to as "alpha blending". As a special case of this technique, a diffuse texture may have its entire alpha channel set to either pure black or pure white, with no grays used. This specialization is often referred to as "alpha masking".
 
  
 
[[Category:Texture mapping]]
 
[[Category:Texture mapping]]

Latest revision as of 13:26, 6 June 2018

The albedo map defines the base RGB color of each texel. It is configured using a texture.txt file which is directly referenced from the material (usually within a mesh file although sometimes from the asset's config.txt directly).

The albedo map is the Physically Based Rendering equivalent of the diffuse map used in legacy materials. At a casual glance, these fill the same role and the terms can be interchanged, however to be strictly accurate the albedo is the surface color irrespective of any lighting effects, whereas the diffuse map frequently included burned-in lighting (pre-baked ambient occlusion, etc.) The albedo map should never include pre-baked lighting, as that would interfere with the correct operation of the PBR equations.

[edit] Color Space

Unless otherwise specified by the material in use, the RGB channels use the sRGB color space.

[edit] Alpha Channel

It is common for (semi-)transparent materials to store the alpha blend factor (ie. opacity level) in the albedo map's alpha channel. Materials which are fully opaque may use the albedo's alpha channel for some other purpose, or not at all.

If no alpha channel is specified, the outcome is identical to a fully white (1.0) alpha channel.

Some legacy material types offer automatic selection of alpha blending, alpha masking or opaque rendering modes based on the contents and configuration of the albedo map. This introduces uncertainties when texture replacement is used as to what material configuration will result. TRS19 materials do not attempt this, and instead rely on the content creator to select the appropriate material type.


[edit] Examples

TBD: See Normal map for examples.

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